Hubble’s successor, the James Webb Space Telescope scheduled for launch in early 2021. I am a core Science Team member for JWST’s NIRISS instrument and we are now getting ready for our 200-hour GTO survey of five lensing clusters fields.

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Taro Sato (postdoctoral fellow)

Jon Savoy (research assistant)

Bobby Sorba (grad student)

Andy Marquis (grad student)

Michael Palmer (undergrad)


  1. Dr. Thibaud Moutard (Post-doctoral fellow):  Mechanisms for the quenching of star formation;  the CLAUDS project

  2. Dr. Gaël Noirot (Post-doctoral fellow): Slitless grism spectroscopy with HST and JWST, high-z galaxy (proto)clusters

  3. Anneya Golob (PhD student): Environment and galaxy evolution; the CLAUDS project

  4. Lingjian Chen (MSc student): Environments of very massive galaxies; the CLAUDS project

  5. Angelo George (MSc student, co-supervised with Dr. Damjanov): Morphologies of quiescent galaxies; the CLAUDS project

  6. Harrison Souchereau (undergraduate research assistant, co-supervised with Dr. Damjanov): galaxy light profiles from deep images; the CLAUDS project


  1. Dr. Robert Sorba, PhD (2017): Using Model Spectral Energy Distributions to Study Galaxy Masses: Now and in the Future

  2. Gurpreet Kaur Cheema, MSc (2017): Clustering of Dark Matter Halos of Ultra-Massive Passively Evolving Galaxies and Passive Galaxy Groups at z~1.6

  3. Dr. Liz Arcila Osejo, PhD (2018): Massive Passive Galaxies at z~1.6

  4. Nathalie Thibert, MSc (2018): Automated Detection of Merging Galaxies at z = 0.25 − 1.0 in the CLAUDS+HSC Survey Using Random Forests

  5. Martin Hellmich, BSc honours thesis (2019): Simulating Hubble XDF Observations for CASTOR and WFIRST

  6. Dr Ikuru Iwata of NAOJ spent a year-long (2018-2019) sabbatical visiting our group and working on the escape of ionizing radiation from high-z galaxies and AGN

Marcin Sawicki
Astronomy & Physics


CLAUDS+HSC Survey (CFTH+Subaru):  

CLAUDS is a Canada-France-China collaboration to obtain deep CFHT U-band imaging in the Subaru Hyper Suprime-Cam (HSC) survey Deep fields. Our U-band imaging greatly enhances the Subaru grizy dataset, allowing the selection of star-forming galaxies at z~2-3, measurement of star formation rates at z<1, and dramatically improving photometric redshift performance of the combined surveys. The CLAUDS data (68 dedicated CFHT dark-time nights plus archival data) are all in hand, and merged with the HSC dataset from our Subaru partners. Together, these catalogs are ideal for a large range of scientific applications from detailed galaxy evolutions studies over 0<z<1, to assembling large samples of galaxies, quasars and protoclusters at z~2-3. We are working on many of these topics, but there is so much science to do with this incredibly rich dataset!

                                                                              more here and here  


The CANUCS project will study high-redshift galaxies with Hubble’s successor, the James Webb Space Telescope. Soon after JWST’s 2021 launch we will be investing 200 hours of guaranteed JWST time into observing distant galaxies behind intermediate-redshift massive lensing clusters. JWST’s superb sensitivity, further boosted through gravitational lensing by the cluster potentials, will let us detect galaxies in the Epoch of Reionization at z~7 and above, and study in detail galaxy structure at “cosmic high noon” around z~2-3.  Preparations for this project are now in progress and observations will start soon after JWST’s launch in the first half of 2021.

  1.                                                             more here


GIRMOS (Gemini InfraRed Multi-Object Spectrograph) is a next-generation instrument now under development for the 8-metre Gemini observatory. It will have the ability to take spatially-resolved spectra of several separate targets at once with light fed through an advanced adaptive optics system. This is a $12.5M, CFI-funded project with first light planned for 2024. I am leading the team that’s developing the GIRMOS observation planning and data reduction software.

                                                                      more here and here


I study the formation and evolution of galaxies at epochs when the Universe was only a fraction of its present age. I am particularly interested in where and when the Universe made its stars and the complex chemical elements that we are all made of. In my work I use space-based facilities including the Hubble and Spitzer Space Telescopes, as well as ground-based ones such as the Gemini, CFHT, and Subaru observatories in Hawaii and Chile. I am a core member of the Canadian James Webb Space Telescope Guaranteed Time Observer (GTO) team and after two decades in development, I look forward to using our JWST GTO time in this research very soon after JWST’s March 2021 launch!


The research of our group is financially supported by the Canada Research Chairs program, NSERC, the Canadian Space Agency, the Canada Foundation for Innovation, the Research Nova Scotia Trust, and Saint Mary’s University, and makes use of ACEnet, Compute Canada, and CANFAR computing resources.  I am also grateful to the NRC Herzberg Astronomy and Astrophysics, Kyoto University, and the Japan Society for the Promotion of Science for hosting and supporting me with great research environments and resources during my current sabbatical year.